The Yakovlev Yak-3 (Russian: Я́ковлев Як-3) was a World War II Soviet fighter aircraft. Robust and easy to maintain, it was much liked by pilots and ground crew alike. It was one of the smallest and lightest major combat fighters fielded by any combatant during the war, and its high power-to-weight ratio gave it excellent performance. It proved a formidable dogfighter. Marcel Albert, World War II French ace, who flew the Yak in USSR with the Normandie-Niémen Group, considered it a superior aircraft to the P-51D Mustang and the Supermarine Spitfire.After the war ended, it flew with the Yugoslav and Polish Air Forces.

The Yak-3U is a Yak-3 fitted with Shvetsov ASh-82FN radial engine with 1,380 kW (1,850 hp) in an attempt to increase performance while avoiding the overheating problems of VK-107 and VK-108. Wingspan increased by 20 cm (8 in), wings moved 22 cm (9 in) forward, cockpit raised by 8 cm (3 in). Armament of 2 × 20 mm Berezin B-20 cannons with 120 rpg. The prototype reached 682 km/h (424 mph) at 6,000 m (19,685 ft) and while successful did not enter production because it was completed after the war.
Flying a modified replica Yak-3U manufactured in Romania in 2005 and powered by a Pratt & Whitney R-2000 engine, William Whiteside set an official international speed record for piston-engined aircraft in the under-3,000 kg (6,615-pound) category on 10 October 2011, reaching 655 km/hr (407 mph) over a 3-km (1.863-mile) course at the Bonneville Salt Flats in Utah in the United States, greatly exceeding the previous record of 491 km (305 mph) set in 2002 by Jim Wright. The following day, Whiteside used the same aircraft to set an unofficial speed record for aircraft in the category of 670 km/hr (416 mph) over the same 3-km (1.863-mile) course.